Riding a Loop-the-loop. A car in an amusement park ride rolls without friction around the track shown in the figure. It starts from rest at point A at a height h above the bottom of the loop. Treat the car as a particle. "http://community.webshots.com/user/mmaddoxwku" [Broken] What is the minimum value of h (in terms of R) such that the car moves around the loop without falling off at the top (point B)? I have no clue what to do.